1. Technical Field
The present invention relates to a piezoelectric element, a piezoelectric actuator, a liquid ejecting head, and a liquid ejecting apparatus.
2. Related Art
A piezoelectric element is an element having a characteristic of changing a shape thereof if a voltage is applied thereto and has a configuration in which a piezoelectric body is sandwiched between electrodes. The piezoelectric element is used for various applications such as a liquid ejecting head portion of an ink jet printer, various actuators, and the like, for example.
In the piezoelectric element, if moisture makes contact with the piezoelectric body, for example, a leak current generated between two electrodes is increased, resulting in deterioration in reliability of the piezoelectric element in some case. As a method of preventing the piezoelectric body from making contact with moisture, for example, a configuration in which the piezoelectric body is covered by an upper electrode has been proposed (see, JP-A-2009-172878).
However, in the configuration in which the piezoelectric body is covered by the upper electrode, stress is concentrated on connecting portions between side surfaces of the piezoelectric body and an upper surface of a substrate (for example, vibration plate) and cracking is generated on the upper electrode covering the connecting portions in some case. As a result, reliability of the piezoelectric element is deteriorated.